Problem: If x cows give x+1 cans of milk in x+2 days, how many days will it take x+3 cows to give x+5 cans of milk?
Answer Choices:
A. (x+1)(x+3)x(x+2)(x+5)​
B. (x+2)(x+3)x(x+1)(x+5)​
C. x(x+2)(x+1)(x+3)(x+5)​
D. x(x+2)(x+5)(x+1)(x+3)​
E. none of these
Solution:
A cow gives x(x+2)(x+1)​ cans per day. Hence (x+3) cows give x(x+2)(x+1)(x+3)​ cans per day, and (x+3) cows give milk at the rate of (x+1)(x+3)x(x+2)​ days per can. To fill (x+5) cans takes (x+1)(x+3)x(x+2)(x+5)​ days.